Apparatus for sequentially transporting containers

Abstract

Apparatus for transferring and manipulating a plurality of containers in a sequence is disclosed including a mechanical manipulator arm 10 having a gripping device B which automatically picks up a container at a fixed pickup position P and transfers it to a processing station. At a processing station X, the container is loaded with silicon wafers and thereafter returned by the arm to the fixed position P at the pickup and return station Y. A plurality of the containers may be processed in sequence from the fixed pickup position by providing a movable carriage 58 upon which container pedestal platforms 54 and 56 are supported, at least one of which is an elevator platform. The platforms include abutments 54c and 56c for properly positioning the containers for accurate pickup by the manipulator arm. Sensing switches may be provided for sensing movements of the arm 10, carriage 58, and elevator platform 56 whereby the entire apparatus may be controlled automatically avoiding the need to handle the wafers manually to reduce the possibility of contamination.

What is claimed is: 
     
       1. Apparatus for manipulating and sequentially transferring containers between a first station at which a container is loaded with silicon wafers and a second station at which said container is initially picked up empty and subsequently returned loaded, said apparatus comprising: a movable arm member movable between said first and second stations;   a gripping device carried adjacent an end of said arm for picking up and securely gripping said container in a stable manner for transportation thereof;   said second station processing a plurality of said containers in sequence including a fixed pickup position from which said containers are picked up individually;   pedestal means upon which said containers are placed having variable positions for supporting said containers individually for pickup and return at said pickup position;   means for properly positioning said containers at said pickup position on said pedestal means for positive engagement by said gripping device of said arm member;   carriage means supporting said pedestal means;   said carriage means being movable between first and second positions to vary said position of said pedestal means and place said containers individually at said pickup position; and   said pedestal means including an elevator platform for supporting a first individual container and lowering said container below the level of a second container when said second container is placed at said pickup position by said carriage means, means, said lowered container affording access for engagement of said second container by said gripping device of said movable arm member.   
     
     
       2. The apparatus of claim 1 wherein said pedestal means includes a plurality of platforms for supporting containers individually; one of said platforms comprising said elevator platform and a second of said platforms supporting and placing said second container at said pickup position when said elevator platform and first container thereon are lowered. 
     
     
       3. The apparatus of claim 2 wherein said means for properly positioning said containers includes abutment means having an abutment carried by said platform and biasing means urging said container against said abutment to so position said container properly thereon. 
     
     
       4. The apparatus of claim 3 wherein said biasing means is provided by said platform being inclined in the direction of said abutment whereby said container moves against said abutment when placed on said platform. 
     
     
       5. The apparatus of claim 4 wherein said abutment means includes a complimentary abutment carried by an underneath portion thereof which engages said platform abutment when said container is placed thereon. 
     
     
       6. The apparatus of claim 2 wherein said platforms are carried by said carriage means, said elevator and second platforms being shifted laterally thereby so that said second platform occupies said fixed pickup position following return of said first container to said elevator platform and lowering thereof. 
     
     
       7. The apparatus of claim 6 including frame means, guide means carried on said frame means for guiding said carriage means for horizontal movement, said carriage means including a lower cantilevered stationary base platformspaced from said second platform, said elevator pedestal platform being carried for relative vertical movement on said lower base platform. 
     
     
       8. The apparatus of claim 1 wherein said gripper device comprises mechanical linkage assembly means having a first lever arm having an arm portion receivable over a side edge of said container and a second lever arm having a container side engaging portion, said first and second arms being pivotable in opposing directions to grip said container therebetween. 
     
     
       9. The apparatus of claim 8 including an inner lever arm means extending past said first and second lever arms having a retaining portion adapted for spanning over the top of said container holding said wafers loaded therein during movement of said container. 
     
     
       10. The apparatus of claim 8 wherein said side engaging portion of said second lever arm includes an elongated bar carried transverse to said second arm. 
     
     
       11. The apparatus of claim 8 including a cantilevered shaft carried by said end of said transfer arm, a bracket assembly having spaced brackets received over said shaft for axial relative movement and roller pins spacing said brackets facilitating sliding of said bracket assembly over said shaft, said roller pins engaging said first and second lever arms to effect said pivotal movement and closure of said grip therebetween. 
     
     
       12. The apparatus of claim 1 including a motor for moving said transfer arm between forward and rear positions at operational positions at said first and second stations, respectively, and stop means for limiting movement of said arm at said forward and rear positions and accurately position said arm for engagement of said containers by said gripping device. 
     
     
       13. The apparatus of claim 12 wherein said stop means includes switch means for terminating operation of said motor at said forward and rear limit positions.